Distúrbios do sono em pacientes com deformidades dentofaciais : correlação com biomarcadores salivares

Abstract

The present observational clinical study aimed to evaluate the presence of sleep disorders in patients with dentofacial deformities (DFD), in preparation for orthognathic surgery (OS), correlating the results of objective and subjective sleep dimensions, with the salivary levels of biomarkers. The research protocol was approved by the Institutional Ethics Committee (PUCRS; approval number 3.343.197). The sample consisted of twenty patients (17-46 years old), divided into two groups of ten men and ten women, matched by age, diagnosed with DFD, under orthodontic treatment, before orthognathic surgery. The participants, assisted at the Oral Surgery Service of the School of Health and Life Sciences of PUCRS answered a general evaluation form. Anatomical and anthropometric data were collected as part of the objective components of sleep assessment. Subsequently, the following questionnaires validated for the Brazilian Portuguese were applied for the subjective analysis of potential sleep alterations: Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Fletcher and Luckett Sleep Questionnaire (FLSQ). The PSQI is an instrument used for general assessment of sleep quality. The ESS aims to measure the propensity to daytime sleep, while the FLSQ consists of questions about sleep, apnea, snoring and daytime sleepiness, for determining the levels of obstructive sleep apnea (OSA) symptoms. In addition, all patients were evaluated by the Biologix® system, a type IV polysomnography test, which aims to monitor oxygen desaturation and snoring, as indicative of symptomatic OSA. Stimulated saliva samples were collected from all patients included in the study. Salivary levels of the inflammatory cytokine, interleukin-1β (IL-1β), were determined by using an ELISA test. Glutamate and serotonin levels were measured by high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS). Demographic variables, questionnaire results and salivary levels of biomarkers were analyzed by Fischer's Exact Test or Student’s unpaired t Test. Pearson's coefficient was used to correlate the data of the questionnaires and the results of the Biologix® system, with the levels of salivary biomarkers. P values less than 0.05 were considered as indicative of significance. The subjective evaluation of sleep quality by the PSQI did not reveal significant differences between males and females. However, 85% of participants presented scores higher than 5 for this questionnaire, suggesting poor sleep quality in DFD individuals, irrespective of sex. There were no significant differences for the ESS instrument or for part 1 of the FLSQ, in the comparison between the sexes. On the other hand, significantly higher scores were observed for females in part 2 of the FLSQ instrument. An analysis of the total FLSQ scores (part 1 + part 2) showed a tendency towards higher values in females. Remarkably, 17 out of 20 patients displayed scores superior to 1 in the FLSQ, as indicative of sleep disturbances. Regarding anatomical features, females presented significantly lower levels of the inferior facial third, with a tendency to smaller levels for the middle third facial, compared with males. No significant difference was observed when comparing the length of the upper facial third, between males and females. As well, no significant differences were detected for neck or alar width, or for tongue length, in the comparison between the sexes. Males presented higher values of abdominal and cervical circumference, although the mean BMI values were similar for both sexes. The evaluation of OSA, through polysomnography with the Biologix® device, did not show significant differences in relation to oxygen/h desaturation indexes or, regarding the number of desaturation episodes, between males and and females. Only three males presented oxygen desaturation values higher than 5, as indicative of symptomatic OSA. The same patients had the highest values of abdominal circumference and BMI. All patients with DFD, regardless of sex, had detectable salivary levels of IL-1β, glutamate, and serotonin. Pearson's coefficient analysis showed a significant negative correlation between salivary serotonin levels and FLSQ results. There was no correlation between serotonin levels and PSQI scores or, with OSA measurements by Biologix®. In addition, there were no significant correlations between salivary levels of IL-1β or glutamate, in relation to sleep questionnaires or polysomnographic evaluation. Our study provides new evidence showing that patients with DFD have reduced salivary serotonin levels, which may be associated with poor sleep quality levels. These findings open new avenues regarding the need of an holistic management as for patients with a DFD.